The company made headlines in 2016 after its AlphaGo program beat a human professional Go player for the first time in October 2015[8] and again when AlphaGo beat Lee Sedol the world champion in a five-game match, which was the subject of a documentary film.[9]

In September 2015, DeepMind and the Royal Free NHS Trust signed their initial Information Sharing Agreement (ISA) to co-develop a clinical task management app, Streams.[26]

After Google's acquisition the company established an artificial intelligence ethics board.[27] The ethics board for AI research remains a mystery, with both Google and DeepMind declining to reveal who sits on the board.[28] DeepMind, together with Amazon, Google, Facebook, IBM, and Microsoft, is a founding member of Partnership on AI, an organization devoted to the society-AI interface.[29] DeepMind has opened a new unit called DeepMind Ethics and Society and focused on the ethical and societal questions raised by artificial intelligence featuring prominent transhumanist Nick Bostrom as advisor.[30] In October 2017, Deepmind launched new 'ethics and society' research team to investigate AI ethics.[31][32]

DeepMind Technologies' goal is to "solve intelligence",[33] which they are trying to achieve by combining "the best techniques from machine learning and systems neuroscience to build powerful general-purpose learning algorithms".[33] They are trying to formalize intelligence[34] in order to not only implement it into machines, but also understand the human brain, as Demis Hassabis explains:

[...] attempting to distil intelligence into an algorithmic construct may prove to be the best path to understanding some of the enduring mysteries of our minds.[35]

Google Research has released a paper in 2016 regarding AI Safety and avoiding undesirable behaviour during the AI learning process.[36] Deepmind has also released several publications via their website.[37] In 2017 DeepMind released GridWorld, an open-source testbed for evaluating whether an algorithm learns to disable its kill switch or otherwise exhibits certain undesirable behaviors.[38][39]

To date, the company has published research on computer systems that are able to play games, and developing these systems, ranging from strategy games such as Go[40] to arcade games. According to Shane Legg human-level machine intelligence can be achieved "when a machine can learn to play a really wide range of games from perceptual stream input and output, and transfer understanding across games[...]."[41] Research describing an AI playing seven different Atari 2600 video games (the Pong game in Video Olympics, Breakout, Space Invaders, Seaquest, Beamrider, Enduro, and Q*bert) reportedly led to their acquisition by Google.[4] Hassabis has mentioned the popular e-sport game StarCraft as a possible future challenge, since it requires a high level of strategic thinking and handling imperfect information.[42]

As opposed to other AIs, such as IBM's Deep Blue or Watson, which were developed for a pre-defined purpose and only function within its scope, DeepMind claims that their system is not pre-programmed: it learns from experience, using only raw pixels as data input. Technically it uses deep learning on a convolutional neural network, with a novel form of Q-learning, a form of model-free reinforcement learning.[2][43] They test the system on video games, notably early arcade games, such as Space Invaders or Breakout.[43][44] Without altering the code, the AI begins to understand how to play the game, and after some time plays, for a few games (most notably Breakout), a more efficient game than any human ever could.[44]

As of 2014[update], DeepMind played below the current World Record for most games, for example Space Invaders, Ms Pac-Man and Q*Bert. DeepMind's AI had been applied to video games made in the 1970s and 1980s; work was ongoing for more complex 3D games such as Doom, which first appeared in the early 1990s.[44]

In October 2015, a computer Go program called AlphaGo, developed by DeepMind, beat the European Go champion Fan Hui, a 2 dan (out of 9 dan possible) professional, five to zero.[45] This is the first time an artificial intelligence (AI) defeated a professional Go player.[8] Previously, computers were only known to have played Go at "amateur" level.[45][46] Go is considered much more difficult for computers to win compared to other games like chess, due to the much larger number of possibilities, making it prohibitively difficult for traditional AI methods such as brute-force.[45][46] In March 2016 it beat Lee Sedol—a 9th dan Go player and one of the highest ranked players in the world—with 4-1 in a five-game match. In the 2017 Future of Go Summit, AlphaGo won a three-game match with Ke Jie, who at the time continuously held the world No. 1 ranking for two years.[47][48] It used a supervised learning protocol, studying large numbers of games played by humans against each other.[49]

In 2017, an improved version, AlphaGo Zero, defeated AlphaGo 100 games to 0. AlphaGo Zero's strategies were self-taught. AlphaGo Zero was able to beat its predecessor after just three days with less processing power than AlphaZero; in comparison, the original AlphaGo needed months to learn how to play.[50]

Later that year, AlphaZero, a modified version of AlphaGo Zero, gained superhuman abilities at chess and shogi solely. Like AlphaGo Zero, AlphaZero learned through self-play.

AlphaGo used two deep neural networks: a policy network to evaluate move probabilities and a value network to assess positions. The policy network trained via supervised learning, and was subsequently refined by policy-gradient reinforcement learning. The value network learned to predict winners of games played by the policy network against itself. After training these networks employed a lookahead Monte Carlo tree search (MCTS), using the policy network to identify candidate high-probability moves, while the value network (in conjunction with Monte Carlo rollouts using a fast rollout policy) evaluated tree positions.[51]

Zero trained using reinforcement learning in which the system played millions of games against itself. Its only guide was to increase its win rate. It did so without learning from games played by humans. Its only input features are the black and white stones from the board. It uses a single neural network, rather than separate policy and value networks. Its simplified tree search relies upon this neural network to evaluate positions and sample moves, without Monte Carlo rollouts. A new reinforcement learning algorithm incorporates lookahead search inside the training loop.[51] AlphaGo Zero employed around 15 people and millions in computing resources.[52] Ultimately, it needed much less computing power than AlphaGo, running on four specialized AI processors (Google TPUs), instead of AlphaGo's 48.[53]

WaveNet is DeepMind's deep generative model of raw audio waveforms. WaveNet was originally too computationally intensive for use in consumer products when it debuted in 2016; however, in late 2017, it became ready for use in consumer applications such as Google Assistant.[54][55]

In August 2016, a research programme with University College London Hospital was announced with the aim of developing an algorithm that can automatically differentiate between healthy and cancerous tissues in head and neck areas.[57]

In April 2016, New Scientist obtained a copy of a data-sharing agreement between DeepMind and the Royal Free London NHS Foundation Trust. The latter operates the three London hospitals where an estimated 1.6 million patients are treated annually. The revelation has exposed the ease with which private companies can obtain highly sensitive medical information without patient consent. The agreement shows DeepMind Health had access to admissions, discharge and transfer data, accident and emergency, pathology and radiology, and critical care at these hospitals. This included personal details such as whether patients had been diagnosed with HIV, suffered from depression or had ever undergone an abortion in order to conduct research to seek better outcomes in various health conditions.[60][61] The agreement is seen as controversial and its legality has been questioned.[28]

In May 2017, Sky News published a leaked letter from the National Data Guardian, Dame Fiona Caldicott, revealing that in her "considered opinion" the data sharing agreement between DeepMind and the Royal Free took place on an "inappropriate legal basis".[64]

The Information Commissioner’s Office ruled in July 2017 that London’s Royal Free hospital failed to comply with the Data Protection Act when it handed over personal data of 1.6 million patients to DeepMind. [65]

As of October 2017, the DeepMind team has expanded their focus to also include AI ethics. With the former Google UK and EU policy manager Sean Legassick leading this new team, their goal is to fund external research of the following themes: privacy transparency and fairness; economic impacts; governance and accountability; managing AI risk; AI morality and values; and how AI can address the world’s challenges. As a result, the team hopes to further understand the ethical implications of AI and aid society to seeing AI can be beneficial.[66]